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/* |
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* pufftest.c |
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* Copyright (C) 2002-2013 Mark Adler |
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* For conditions of distribution and use, see copyright notice in puff.h |
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* version 2.3, 21 Jan 2013 |
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*/ |
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|
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/* Example of how to use puff(). |
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|
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Usage: puff [-w] [-f] [-nnn] file |
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... | puff [-w] [-f] [-nnn] |
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|
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where file is the input file with deflate data, nnn is the number of bytes |
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of input to skip before inflating (e.g. to skip a zlib or gzip header), and |
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-w is used to write the decompressed data to stdout. -f is for coverage |
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testing, and causes pufftest to fail with not enough output space (-f does |
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a write like -w, so -w is not required). */ |
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|
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#include <stdio.h> |
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#include <stdlib.h> |
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#include "puff.h" |
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|
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#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__) |
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# include <fcntl.h> |
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# include <io.h> |
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# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) |
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#else |
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# define SET_BINARY_MODE(file) |
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#endif |
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|
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#define local static |
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|
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/* Return size times approximately the cube root of 2, keeping the result as 1, |
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3, or 5 times a power of 2 -- the result is always > size, until the result |
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is the maximum value of an unsigned long, where it remains. This is useful |
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to keep reallocations less than ~33% over the actual data. */ |
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local size_t bythirds(size_t size) |
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{ |
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int n; |
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size_t m; |
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|
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m = size; |
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for (n = 0; m; n++) |
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m >>= 1; |
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if (n < 3) |
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return size + 1; |
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n -= 3; |
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m = size >> n; |
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m += m == 6 ? 2 : 1; |
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m <<= n; |
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return m > size ? m : (size_t)(-1); |
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} |
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|
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/* Read the input file *name, or stdin if name is NULL, into allocated memory. |
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Reallocate to larger buffers until the entire file is read in. Return a |
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pointer to the allocated data, or NULL if there was a memory allocation |
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failure. *len is the number of bytes of data read from the input file (even |
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if load() returns NULL). If the input file was empty or could not be opened |
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or read, *len is zero. */ |
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local void *load(const char *name, size_t *len) |
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{ |
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size_t size; |
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void *buf, *swap; |
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FILE *in; |
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|
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*len = 0; |
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buf = malloc(size = 4096); |
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if (buf == NULL) |
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return NULL; |
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in = name == NULL ? stdin : fopen(name, "rb"); |
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if (in != NULL) { |
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for (;;) { |
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*len += fread((char *)buf + *len, 1, size - *len, in); |
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if (*len < size) break; |
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size = bythirds(size); |
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if (size == *len || (swap = realloc(buf, size)) == NULL) { |
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free(buf); |
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buf = NULL; |
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break; |
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} |
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buf = swap; |
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} |
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fclose(in); |
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} |
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return buf; |
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} |
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|
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int main(int argc, char **argv) |
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{ |
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int ret, put = 0, fail = 0; |
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unsigned skip = 0; |
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char *arg, *name = NULL; |
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unsigned char *source = NULL, *dest; |
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size_t len = 0; |
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unsigned long sourcelen, destlen; |
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|
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/* process arguments */ |
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while (arg = *++argv, --argc) |
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if (arg[0] == '-') { |
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if (arg[1] == 'w' && arg[2] == 0) |
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put = 1; |
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else if (arg[1] == 'f' && arg[2] == 0) |
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fail = 1, put = 1; |
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else if (arg[1] >= '0' && arg[1] <= '9') |
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skip = (unsigned)atoi(arg + 1); |
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else { |
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fprintf(stderr, "invalid option %s\n", arg); |
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return 3; |
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} |
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} |
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else if (name != NULL) { |
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fprintf(stderr, "only one file name allowed\n"); |
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return 3; |
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} |
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else |
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name = arg; |
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source = load(name, &len); |
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if (source == NULL) { |
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fprintf(stderr, "memory allocation failure\n"); |
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return 4; |
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} |
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if (len == 0) { |
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fprintf(stderr, "could not read %s, or it was empty\n", |
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name == NULL ? "<stdin>" : name); |
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free(source); |
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return 3; |
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} |
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if (skip >= len) { |
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fprintf(stderr, "skip request of %d leaves no input\n", skip); |
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free(source); |
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return 3; |
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} |
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|
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/* test inflate data with offset skip */ |
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len -= skip; |
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sourcelen = (unsigned long)len; |
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ret = puff(NIL, &destlen, source + skip, &sourcelen); |
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if (ret) |
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fprintf(stderr, "puff() failed with return code %d\n", ret); |
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else { |
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fprintf(stderr, "puff() succeeded uncompressing %lu bytes\n", destlen); |
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if (sourcelen < len) fprintf(stderr, "%lu compressed bytes unused\n", |
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len - sourcelen); |
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} |
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|
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/* if requested, inflate again and write decompressd data to stdout */ |
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if (put && ret == 0) { |
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if (fail) |
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destlen >>= 1; |
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dest = malloc(destlen); |
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if (dest == NULL) { |
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fprintf(stderr, "memory allocation failure\n"); |
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free(source); |
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return 4; |
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} |
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puff(dest, &destlen, source + skip, &sourcelen); |
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SET_BINARY_MODE(stdout); |
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fwrite(dest, 1, destlen, stdout); |
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free(dest); |
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} |
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|
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/* clean up */ |
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free(source); |
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return ret; |
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} |